Supporting structure of plastic construction for a formwork panel

ABSTRACT

A supporting structure of plastic construction for a formwork panel, comprising a supporting structure and a formwork skin which is positioned on the front side of the supporting structure and attached to the supporting structure, wherein the supporting structure has two longitudinal edge supports and two transverse edge supports, 
     characterized in that the supporting structure comprises a main body made of plastic, to which the two longitudinal edge supports and the two transverse edge supports belong, and, in the region of the front sides of the two longitudinal edge supports and/or of the two transverse edge supports, has an edge protection provided for protecting at least part of the edge of the formwork skin after attachment thereof to the supporting structure, wherein the edge protection is made of a material different from the material of said supports of the supporting structure and has a portion projecting forward from the respective said support; and/or 
     in that the supporting structure has a main body made of plastic, to which the two longitudinal edge supports and the two transverse edge supports belong, and, in the region of the front sides of the two longitudinal edge supports and/or of the two transverse edge supports, and/or in the region of the rear sides of the two longitudinal edge supports and/or of the two transverse edge supports, has a reinforcement made of a material different from the material of said supports of the supporting structure.

Subject matter of the invention is a supporting structure of plastic construction for a formwork panel, which comprises a supporting structure and a formwork skin which is positioned on the front side of the supporting structure and attached to the supporting structure, wherein the supporting structure has two longitudinal edge supports and two transverse edge supports,

characterized in that the supporting structure has a main body made of plastic, to which the two longitudinal edge supports and the two transverse edge supports belong, and, in the region of the front sides of the two longitudinal edge supports and/or of the two transverse edge supports, has an edge protection provided for protecting at least part of the edge of the formwork skin after attachment thereof to the supporting structure, wherein the edge protection is made of a material different from the material of said supports of the supporting structure and has a portion projecting forward from the respective said support; and/or

in that the supporting structure has a main body made of plastic, to which the two longitudinal edge supports and the two transverse edge supports belong, and in the region of the front sides of the two longitudinal edge supports and/or of the two transverse edge supports, and/or in the region of the rear sides of the two longitudinal edge supports and/or of the two transverse edge supports, has a reinforcement made of a material different from the material of said supports of the supporting structure.

Supporting structures of plastic construction for formwork panels are known. As compared to supporting structures made of wood or metal, they offer a whole range of advantages: high durability, low weight, low aging, cost-effective manufacture and favorable recyclability. The following items are to be noted on the negative side: In order to achieve high strength values, efforts are required in the construction, and the practical design of the transition to the formwork skin is a challenge.

In the present application, the term “edge of the formwork skin” is understood to mean the contour area of the formwork skin, extending from the formwork skin front side (which is the shaping surface for the concrete) to the formwork skin rear side. The term “edge of the formwork skin” is not intended to denote e.g. the line at which the area of the formwork skin front side intersects with the contour area of the formwork skin, and is not intended to denote e.g. a line at which a virtual plane on the rear side of the formwork skin, parallel to the formwork skin front side, intersects with the contour area of the formwork skin.

According to a first aspect, the supporting structure according to the invention has an edge protection for protecting at least part of the edge of the formwork skin after attachment thereof to the supporting structure. The edge of the formwork skin is a comparatively sensitive formwork skin region on which damages may be caused relatively easily, be it when erecting a formwork from formwork panels positioned close to each other, be it when handling the formwork panels in rough construction site operation. This sensitivity is particularly pronounced when formwork panels having a supporting structure of plastic are used. According to its first aspect, the invention provides a supporting structure with a very effective provision for protecting the edge of the formwork skin to be attached to the supporting structure. The projecting portion of the edge protection which has been mentioned at the beginning can project so far that the outline of the formwork skin is protected up to the transition to the front side of the formwork skin. There are embodiments of the supporting structure according to the invention in which no part of the edge of the formwork skin remains unprotected, i.e. the edge protection is correspondingly complete.

According to a second aspect, the supporting structure according to the invention has, in the region of the front sides of the two longitudinal edge supports and/or of the two transverse edge supports, and/or in the region of the rear sides of the two longitudinal edge supports and/or of the two transverse edge supports, a reinforcement made of a material which is different from the material of said supports of the supporting structure. The provision of such a reinforcement indeed means that the supporting structure becomes more complicated. On the advantage side, however, there is an increase in the load-bearing capacity of the supporting structure, which is achieved more favorably in terms of weight than would be possible e.g. by increased use of plastic material in the supporting structure. The reinforcement in the region of the front sides of the two longitudinal edge supports and/or of the two transverse edge supports can be designed at the same time as the edge protection described. Or expressed in a different viewing direction: The described edge protection can be designed in such a way that it at the same time has the function of a reinforcement in the relevant portions of the supporting structure.

There are embodiments in which the supporting structure according to the invention has an edge protection and/or a reinforcement which consists of a separately manufactured part or of a plurality of separately manufactured parts which is or are combined with the supporting structure main body after manufacture of the same. However, it is alternatively possible to incorporate the edge protection and/or the reinforcement in the course of the manufacture of the main body of the supporting structure into the relevant portion of the main body.

The supporting structure according to the invention, as has been disclosed in the preceding part of the description, can additionally be characterized in that the edge protection and/or the (respective) reinforcement contains a plurality of material strips. The expression “the (respective) reinforcement” was chosen because, in the first paragraph of the description, two types of reinforcement are mentioned, namely a reinforcement associated with the front side of the supporting structure (or the front sides of the two longitudinal edge supports and/or the front sides of the two transverse edge supports), and a reinforcement associated with the rear side of the supporting structure (or the rear sides of the two longitudinal edge supports and/or the rear sides of the two transverse edge supports). The construction of the edge protection and/or the (respective) reinforcement of material strips offers the advantage of permitting cost-effective manufacture. In addition, the material strips can be used in a targeted manner where edge protection and/or reinforcement are most likely required.

An alternative possibility consists in that the edge protection and/or the (respective) reinforcement has the shape of a rectangular frame. This edge protection and/or this reinforcement are particularly comprehensive in their function, and the frame can be combined very efficiently with the main body of the supporting structure.

It is emphasized that hybrid solutions of the two aforementioned possibilities are possible as well, in particular edge protection (which is at the same time reinforcement for the front side of the supporting structure) as a frame and reinforcement made of a plurality of material strips for the rear side of the supporting structure. The exemplary embodiments further below will demonstrate this more clearly.

The supporting structure according to the invention, as disclosed in the preceding part of the description, may additionally be characterized in that the edge protection—as seen in a cross-sectional plane perpendicular to the longitudinal extension of the respective support—has a first leg substantially parallel to the front side of the respective support and a second leg projecting forward from the first leg. This structure optimally brings together the functions of uniting the edge protection with the supporting structure main body and protecting the edge of the formwork skin. The design may be such that the edge protection includes or consists of substantially only these two legs. Alternatively, the edge protection may have further features, e.g. a third leg projecting rearwardly from the first leg.

The supporting structure according to the invention, as disclosed in the preceding part of the description, may further be characterized in that the respective reinforcement—as viewed in a cross-sectional plane perpendicular to the longitudinal extension of the respective support—has a lying or horizontal rectangular cross-section. The term “lying rectangular cross-section” means that—as seen in said cross-sectional plane—the cross-section of the reinforcement has a longer dimension measured parallel to the front or rear side of the main body and a shorter dimension (in most cases a significantly shorter dimension) measured perpendicular thereto. Reinforcements with this geometry are particularly easy to manufacture and to unite with the main body.

As far as the material of the edge protection according to the invention and/or the (respective) reinforcement according to the invention is concerned, metal or elements made of long-fiber-reinforced plastic are good possibilities. In the case of metal, in particular steel or light metal (here in particular aluminum, aluminum alloys and magnesium) are possible. The edge protection or its parts and/or the reinforcement(s) or their parts can be sheet metal parts. In the case of elements made of long-fiber-reinforced plastic, in particular thermoset plastic parts with long fibers embedded therein, e.g. glass fibers, aramid fibers and carbon fibers, are to be mentioned.

It is pointed out at this point that, according to the invention, reinforcements made of metal can be designed as sheet metal parts, the main plane of which is substantially parallel to the front side of the main body. The edge protection according to the invention can be formed as one sheet metal part or a plurality of sheet metal parts (each) with a bent-up edge for the edge protection function.

The supporting structure according to the invention, as disclosed in the preceding part of the description, may further be characterized in that the edge protection and/or the (respective) reinforcement comprises holes and the respective support comprises, on its front side and/or on its rear side, a plurality of extensions each projecting into one of said holes. The series of holes may, but need not, be rectilinear; the only thing of relevance here is that, in the edge protection and/or the reinforcement, a plurality of holes is provided along the respective support. The form-fitting or positive hole/extension engagements cause the edge protection or reinforcement to be anchored to the respective support in a shear-resistant manner, so that the edge protection and the respective support, or the reinforcement and the respective support, form a unit in terms of the load-bearing capacity of the supporting structure. “Shear-resistant” in this context means that forces acting parallel to the front side of the supporting structure are transmitted in a form-fitting or positive manner.

The supporting structure according to the invention, as disclosed in the preceding part of the description, may further be characterized in that the edge protection and/or the (respective) reinforcement is at least partially embedded in the plastic material of the respective support. A typical example of how such embedding may be manufactured will be explained below in connection with a manufacturing process according to the invention. The being embedded can go so far that at least the respective part of the edge protection or reinforcement is enclosed all around by the plastic material of the respective support. However, it is also possible to go less far and, for example, embed the edge protection or reinforcement in the plastic material of the support only on three sides, as it were, leaving a fourth side uncovered by the plastic material. Embedding in the plastic material of the respective support can also be combined with the hole/extension engagement described in the preceding paragraph.

The supporting structure according to the invention, as disclosed in the preceding part of the description, may further be characterized in that its main body comprises the two longitudinal edge supports, the two transverse edge supports and a plurality of transverse intermediate supports. The design may be such that the main body has no other supports, or no other parts at all, other than these aforementioned supports. However, the design may also be such that the main body has further parts, e.g. longitudinal intermediate supports. The main body may be a one-piece or integral plastic part. The main body may be an integral injection molded plastic part. The main body may be made of fiber-reinforced plastic, in particular glass fiber-reinforced plastic.

The supporting structure according to the invention, as disclosed in the preceding part of the description, may additionally be characterized in that the two longitudinal edge supports and/or the two transverse edge supports are formed as double walls with two partial walls and with first connecting walls therebetween, which have extension planes transverse to the longitudinal extension direction of the respective support. Alternatively or additionally, the two longitudinal edge supports and/or the two transverse edge supports may be formed as double walls with two partial walls and with a second connecting wall therebetween on the front side of the double wall or with a third connecting wall therebetween on the rear side of the double wall. The described double wall designs of the two longitudinal edge supports and/or the two transverse edge supports result in a supporting structure in which the material utilization of the plastic material is optimized.

The supporting structure according to the invention, as disclosed in the preceding part of the description, may additionally be characterized in that at least a partial number of the transverse intermediate supports has two partial walls which are spaced further apart from one another on the side closer to the front side of the supporting structure than on the side further away from the front side of the supporting structure. As seen in a sectional view transverse to the longitudinal direction of extension of the transverse intermediate supports, a trapezoidal shape or a triangular shape are typical embodiments.

The supporting structure according to the invention, as disclosed in the preceding part of the description, may additionally be characterized in that at least a partial number of the transverse intermediate supports—as measured perpendicular to the front side of the supporting structure—is of lesser height than the supporting structure and, on the side further away from the front side of the supporting structure, terminates at a distance from the rear side of the supporting structure. In other words, at least a partial number of the transverse intermediate supports occupies only part of the height of the supporting structure.

The embodiments described in the two preceding paragraphs are favorable in terms of material utilization on plastic.

The supporting structure according to the invention, as disclosed in the preceding part of the description, may further be characterized in that on its front side there is a supporting plane for the formwork skin, to which supporting plane regions on the front sides of the two longitudinal edge supports, regions on the front sides of the two transverse edge supports and regions on the front sides of the transverse intermediate supports contribute. In this case, once the formwork skin is attached to the supporting structure, it is supported by the longitudinal edge supports, the transverse edge supports and the respective transverse intermediate supports, so that it is possible to achieve formwork skin support with relatively small support distances.

It is emphasized that the supporting structure, as disclosed in the six preceding paragraphs, constitutes a separate invention even without the presence of the edge protection disclosed in this application and/or without the presence of the reinforcement or reinforcements disclosed in this application. The novelty in this case resides in the disclosed construction of the main body or supporting structure. What has been said in the two preceding sentences also applies to a formwork panel comprising said supporting structure and a formwork skin attached to the supporting structure, in particular made of plastic.

A further subject matter of the invention is a formwork panel, characterized in that it comprises a supporting structure according to the invention, as disclosed in the preceding part of the description, and a formwork skin positioned on the front side of the supporting structure and attached to the supporting structure. The formwork skin may be made of plastic.

The formwork panel according to the invention can further be characterized in that the edge protection and/or the reinforcement provided in the region of the front sides of the respective supports is positioned in sandwich-like manner between the respective supports of the supporting structure and the formwork skin, and in that, by fastening of the formwork skin to the supporting structure, there is formed at the same time a fastening of the edge protection and/or the reinforcement to the supporting structure. This is a particularly efficient way of integrating the edge protection and/or the respective reinforcement into the formwork panel. In the formwork panel according to the invention, as disclosed in the preceding part of the description, the formwork skin may have clip extensions formed on its rear side, by means of which it is attached to the supporting structure. Alternatively, the formwork skin may have extensions formed on its rear side, and the formwork skin may be attached to the supporting structure by means of screws that are threadedly engaged in at least a partial number of these extensions from the rear side of the supporting structure. “Threadedly engaged in” means that the screw in question is positively seated in the material of the supporting structure. The screws may be self-tapping screws. When making use of screws for fastening the formwork skin to the supporting structure, a possibility according to the invention consists in that at least a partial number of these screws is each passed through a hole of the reinforcement provided in the region of the rear sides of the respective supports, whereby this reinforcement is fastened to the supporting structure. Thus, each screw may serve both for fastening the edge protection and/or the reinforcement provided in the region of the front sides of the respective supports and for fastening the reinforcement provided in the region of the rear sides of the respective supports.

A further subject matter of the invention is a method of manufacturing a supporting structure according to the invention as disclosed in the preceding part of the description, characterized in that the edge protection is at least partially and/or the reinforcement is at least partially positioned in an injection mold and is at least partially embedded in the plastic material of the supporting structure by overmolding during injection molding of the supporting structure. “Overmolding” refers to a manufacturing method in which plastic, in particular during injection molding, embeds a part previously placed in the injection mold—at least on one side—in such a way that a unitary component is manufactured in close connection of the two components.

It is pointed pout here that in the present application the term edge protection refers collectively to the several components which together form the edge protection (insofar as the edge protection consists of several components). The same applies correspondingly for the reinforcement provided in the region of the front sides of the respective supports and for the reinforcement provided in the region of the rear sides of the respective supports (insofar as these each consist of several components at all).

The invention and more specific embodiments of the invention will be explained in more detail below with reference to exemplary embodiments illustrated in drawings, wherein:

FIG. 1 shows a supporting structure for a formwork panel, in a perspective view and as seen looking from diagonally above onto the front side of the supporting structure;

FIG. 2 shows a section of FIG. 1 in an enlarged scale;

FIG. 3 shows a sectional view according to III-III in FIG. 1;

FIG. 4 shows a sectional view according to IV-IV in FIG. 2;

FIG. 5 shows a main body of the supporting structure of FIG. 1, after removal of an edge protection, in a perspective view and as seen looking from diagonally above onto the front side of the main body;

FIG. 6 shows a detail of FIG. 5 in an enlarged scale;

FIG. 7 shows an edge protection, as it was part of the supporting structure in FIGS. 1-4, in a perspective view and as seen looking from diagonally above onto the front side of the edge protection;

FIG. 8 shows a detail of FIG. 7 in an enlarged scale;

FIG. 9 shows a sectional view according to IX-IX in FIG. 7;

FIG. 10 shows a formwork panel consisting of a supporting structure with edge protection and a formwork skin attached to the supporting structure, in a sectional view in the transverse direction of the formwork panel;

FIG. 11 shows a detail of FIG. 10 in an enlarged scale;

FIG. 12 shows a formwork skin, as part of the formwork panel of FIG. 10, in a perspective view and as seen looking from diagonally above onto the rear side of the formwork skin;

FIG. 13 shows a section of FIG. 12 in an enlarged scale;

FIG. 14 shows the formwork panel of FIG. 10, in a perspective exploded view and as seen looking from diagonally above onto the rear side of the formwork panel;

FIG. 15 shows the formwork panel of FIG. 14 in the assembled state, in a perspective view and as seen looking from diagonally above onto the formwork skin;

FIG. 16 shows the formwork panel of FIG. 15, in a perspective view and as seen looking from diagonally above onto the rear side of the formwork panel;

FIG. 17 shows a section of a second embodiment of a formwork panel, in a sectional view in the transverse direction of the formwork panel as in FIG. 11;

FIG. 18 shows a detail of the formwork skin provided in the formwork panel of FIG. 17, in a perspective view and as seen looking from diagonally above onto the rear side of the formwork skin, as in FIG. 13;

FIG. 19 shows a section of a third embodiment of a formwork panel, in a sectional view in the transverse direction of the formwork panel, as in FIGS. 11 and 17;

FIG. 20 shows a section of a fourth embodiment of a formwork panel, which additionally has a reinforcement in the region of the rear sides of the two longitudinal edge supports, in a sectional view in the transverse direction of the formwork panel, as in FIGS. 11, 17 and 19;

FIG. 21 shows the formwork panel of FIG. 20, in a perspective exploded view and as seen looking from diagonally above onto the rear side of the formwork panel;

FIG. 22 shows a fifth embodiment of a supporting structure, in a sectional view in the transverse direction of the supporting structure, as in FIGS. 4, 11, 17 and 19;

FIG. 23 shows a detail of the sectional view of FIG. 22 in an enlarged scale.

The supporting structure 2 shown in FIG. 1 comprises a main body 4 made of plastic and an edge protection 12 made of metal for protecting the edge of a formwork skin to be attached to the supporting structure 2 (cf. FIGS. 10-16). The main body 4 is generally rectangular in plan view. The edge protection 12 has the shape of a rectangular frame in plan view.

The side of the supporting structure 2 facing upward in FIG. 1 (or the upper end portion of the supporting structure 2 in FIG. 1) is the front side 80 thereof. The opposite side of the supporting structure 2 facing downward in FIG. 1 (or the lower end portion of the supporting structure 2 in FIG. 1) is the rear side 82 thereof.

The main body 2 has two longitudinal edge supports 6, two transverse edge supports 8 and, in this exemplary embodiment, a total of seven transverse intermediate supports 10. The main body 4 is a one-piece or integral injection molded part made of plastic. The transverse edge supports 8 are disposed at right angles to the longitudinal edge supports 6 and are about half as long as the longitudinal edge supports 6. The transverse intermediate supports 10 run parallel to the transverse edge supports 8. In the exemplary embodiment illustrated, the longitudinal edge supports 6 have a length—as measured externally over all—of slightly less than 2 m and the transverse edge supports 8 have a length—as measured externally over all—of slightly less than 1 m. Other formats of the main body 4 are possible. Further geometric details of the supports 6, 8,10 will be described further below.

The edge protection 12 is seen in more detail in FIGS. 2, 3, 4. The edge protection 12 is in one piece and has the shape of a rectangular frame with a large free interior space, with the four sections 14 of the edge protection 12 adjoining each other across corners, each section having a width 16—as measured transversely to the longitudinal extension of the section 14. The width 16 is such that the respective section 14 almost completely covers the width of the associated longitudinal edge support 6 or the width of the associated transverse edge support 8. Further details in this regard will be described further below. As seen in a cross-sectional plane perpendicular to the longitudinal extension of the respective support 6 or 8 (cf. FIGS. 3 and 4), the respective section 14 of the edge protection 12 has the shape of a lying or horizontal rectangle with a bent-up, lateral edge 18 along the respective outer edge of the supporting structure 2. The thickness 20 of the cross-sectional rectangle, as measured vertically in FIGS. 3 and 4, is small compared to the width 16. The edge protection 12 is a sheet metal part (sheet thickness=thickness 20) which has been stamped and bent up all around the edge. Apart from the edge 18, the edge protection 12 is arranged parallel to the front side 80 of the supporting structure 2, on which front side 80 a formwork skin will be positioned to create a formwork panel.

In FIG. 2, it can be seen particularly clearly that each of the four sections 14 of the edge protection 12 has a series of e.g. round holes 22 along its outer edge. In the embodiment illustrated, there are thirty-nine holes along each longitudinal edge section 14 and twenty holes 22 along each transverse edge section 14. As is best seen in FIGS. 5 and 6, each longitudinal edge support 6 and each transverse edge support 8 has a series of, in a plan view, circular short extensions 24 on its front side. The positioning and size of the extensions 24 are matched to the holes 22 of the edge protection 12. When the main body 4 and the edge protection 12 are assembled, the extensions 24 each enter into one of the holes 22, as is best seen in FIG. 3. This multiple hole 22/extension 24 engagement creates an overall positive fixed engagement of the edge protection 12 with the front side 80 of the main body 4, with this positive engagement being effective with respect to forces acting parallel to the front side of the main body 4.

Each of the four sections 14 of the edge protection 12 has a series of holes 16 which are rectangular in plan view. The holes 26 are positioned along the inner edge of the edge protection 12. In total, there are nine holes 26 along each longitudinal edge support 6 and five holes 26 along each transverse edge support 8 in this embodiment.

FIGS. 3 and 4 show particularly clearly a longitudinal edge support 6 in a sectional view transverse to the longitudinal extension of the longitudinal edge support 6. Each of the transverse edge supports 8 looks the same in a sectional view perpendicular to its longitudinal extension. The cross-sectional shape of the edge supports 6 and 8 may be described as a double wall with two partial walls 28 and extending between the front side and the rear side of the main body 4. On the rear side 82 of the main body 4, the two partial walls 28 and 30 are connected to each other by a third connecting wall 32 that is parallel to the front side 80 of the main body 4. On the front side 80 of the main body 4, there is no connecting wall lying in the plane of this front side 80. In the region of the front side 80 of the main body 4, each longitudinal edge support 6 and each transverse edge support 8 has a flange 34 directed outwardly (i.e. away from the center of the main body 4). The described extensions 24 are provided on the front side of the flange 34. The edge protection 12 rests with its first leg 36, which is parallel to the front side 80 of the main body 4, on the front side of the flange 34 and covers the space between the two partial walls 28 and 30. The first leg 36 terminates at the outwardly facing side of the inner partial wall 30, but could also still rest on the front side of the inner partial wall 30. On the outside, the first leg 36 is so wide that it extends a short distance beyond the end of the flange 34 before it merges into a second leg 37 (=bent up edge 18) which runs at right angles to the first leg 36. The transition from the first leg 36 into the second leg 37 is a rounded portion with a relatively small bending radius. In FIG. 6, it can be seen that in the longitudinal edge supports 6 and in the transverse edge supports 8, the two partial walls 28 and 30 are connected to one another by a series of spaced apart first connecting walls 38. The first connecting walls 38 each have a plane of extension which is at right angles transverse to the longitudinal extension direction of the respective support 6 or 8.

As can best be seen in FIG. 4, the rectangular holes 26 of the edge protection 12 are positioned such that they are disposed in front of the clearance between the two partial walls 28 and 30. Holes 40 are provided in the third connecting wall 32, each at a position aligned with the position of a rectangular hole 26. The function of the pairs of holes 26 and 40 will described further below.

FIGS. 5 and 6 show the main body 4 without the edge protection 12, so that one can see into the space between the two partial walls 28 and 30 at the longitudinal edge walls 6 and the transverse edge walls 8.

In FIGS. 7, 8, 9, the edge protection 12 is shown by itself.

FIGS. 10, 11, 14, 15, 16, 17, 19, 20, 21, 22, 23 show a formwork panel 50 as manufactured by attaching a formwork skin 52 to the supporting structure 2 described so far or to the supporting structure 2 to be described in second to fifth embodiments. In the embodiment illustrated, the formwork skin 52 is made of plastic and has the shape of a plate with extensions 60, to be described further below, on its rear side facing downward in FIG. 10. This plate, as compared to its plan view size of substantially 2×1 m, has a small thickness of a few centimeters. The formwork skin 52 has such a plan view size that it fits tightly onto and within the edge protection 12, with an edge portion 54 of the formwork skin 52 resting all around on the first leg 36 of the edge protection 12 and the front-side end of the inner partial wall 30, and with the edge 56 of the formwork skin 52 being surrounded all around by the second leg 37 or the bent-up edge 18 of the edge protection 12. The second leg 37 of the edge protection 12 projects so far forward from the front side of the respective longitudinal edge support 6 or transverse edge support 8 that the edge 56 of the formwork skin 52 is just completely covered. The front side of the formwork skin 52 facing upward in FIG. 10 is arranged in the same plane as the upper end of the second leg 37 of the edge protection 12 in FIGS. 10 and 11.

The aforementioned rear extensions 60 of the formwork skin 52 are positioned and dimensioned such that they each fit into one of the described holes 26 of the edge protection 12. The shape of the extensions 60 is best seen in FIGS. 11 and 13. Adjacent the formwork skin rear side, the extensions 60 have a rectangular shape for part of their length—as measured vertically in FIGS. 10 and 11—with which they each fit tightly into one of the holes 26. For the remainder of the length, the respective extension 60 is externally cylindrical with two small stiffening ribs. For at least a portion of its length, the respective extension 60 is hollow on the inside. At each pair of extension 60 and hole 40 in the third connecting wall 32 of the two partial walls 28 and 30 of the respective longitudinal edge support 6 or transverse edge support 8, a screw 62 is threadedly engaged from the, in FIG. 10 lower, rear side 82 of the supporting structure 2 or formwork panel 50. With its upper end portion in FIGS. 10 and 11, the screw 62 is threadedly engaged in a cavity 59 of the associated extension 60 and is thus positively connected to the inner circumference of the cavity 59. The head 64 of the screw 62 is seated at the rear end of the respective hole 40 in the third connecting wall 32. Thus, the screws 62 pull the formwork skin 52 with the flat part of its rear side against the first leg 36 of the edge protection 12, the inner partial wall 30 of the edge supports 6 and 8, and, as will be described in more detail below, the front sides of the transverse intermediate supports 10. As a result, the edge protection 12 is clamped in positionally accurate manner, as it were, between the main body 4 and the formwork skin 52.

Looking at FIGS. 1 and 14, it can be seen that the transverse intermediate supports—as seen in a sectional view transverse to their longitudinal extension—have a cross-section in the form of an open trapezoid. The open, larger trapezoidal side is located on the front side 80 of the main body 4. The shorter, closed trapezoidal side 67 is located approximately halfway between the front side 80 and the rear side 82 of the main body 4. On the open trapezoidal side, there is a narrow flange 68 on each of the left and right sides, which projects in the direction of the length of the main body 4 (cf. FIG. 2). Each transverse intermediate support 10 has four connecting walls 70 distributed along its length. The width of each transverse intermediate support 10—as measured in the longitudinal direction of the main body 4—is substantially equal to the clear distance between two adjacent transverse intermediate supports 10 or between the last transverse intermediate support 10 and the respective transverse edge support 8. The front sides of the flange 68 are in the same plane as the front side of the first leg 36 of the edge protection 12 and the front end of the inner partial wall 30 of the edge supports 6 and 8, respectively. All of this together is located in a common plane which serves as a supporting plane or, in sum, as a supporting surface for the formwork skin 52.

The exploded view of FIG. 14 shows once again how the components main body 4, edge protection 12 and formwork skin 50 are assembled by means of the screws 62. FIGS. 15 and 16 illustrate the formwork panel 50 in its fully assembled state.

The second exemplary embodiment of FIGS. 17 and 18 differs from the exemplary embodiment described so far in that the two partial walls 28 and 30 of the longitudinal edge supports 6 and of the transverse edge supports 8 are respectively connected on the front side of the double wall by a second connecting wall 72, which is parallel to the front side 80 of the main body 4. A third connecting wall 32, as was present in the first embodiment example, is not present in the second exemplary embodiment. In the second embodiment, the extensions 60 on the rear side of the formwork skin 52 are in the form of clip extensions 60. Instead of the rectangular holes 26, round holes 74 are provided in the edge protection 12. The formwork skin 52 is connected to the supporting structure 4 with little effort by inserting its clip extensions 72 through the described holes 74 in the edge protection 12 and through holes 76 aligned therewith in the respective, second connecting wall 72. When fully inserted, the end portions of the clip extensions 60 elastically diverge and are latched behind the rear side of the respective, second connecting wall 72.

In the third exemplary embodiment shown in FIG. 19, the width 16 of the edge protection 12 is smaller than in the previous embodiments. The edge protection 12 no longer extends beyond the clearance between the two partial walls 28 and 30 of the respective longitudinal edge support 6 or transverse edge support 8. In each edge support 6 or 8, as in the first exemplary embodiment, a third connecting wall 32 is provided on the rear side, but no second connecting wall 72 as was present in the second exemplary embodiment. The rear extensions 60 of the formwork skin 50 are configured to fit tightly within the clearance between the two walls 28 and of the respective edge support 6 or 8. As in the first embodiment, screws 62 each extend into a cavity 59 of an extension 60 from the rear side of the main body 4.

The fourth exemplary embodiment shown in FIGS. 20 and 21 differs from the first exemplary embodiment in that a reinforcement 84 is provided in the longitudinal edge supports 6 in the region of the rear sides. The reinforcement 84 includes two strip-shaped members 86 of metal. In this embodiment, the strip-shaped members 86 are each stamped from sheet metal. The strip-shaped members 86 are each as long as the longitudinal edge supports 6 on their rear sides. The strip-shaped members 86 each have a series of 39 holes 22. Projecting into 30 of these holes 22 is in each case a rear extension 24 of the respective longitudinal edge support 6, as has been described in the first embodiment for the front side 80 of the supporting structure 2. However, in the embodiment of FIGS. 20 and 21, the holes 22 are located approximately in the middle of the width 16 of the respective strip-shaped member 86.

A screw 62 extends through each of the remaining 9 holes 22 distributed along the length of the respective strip-shaped member 86, and a hole 88 is provided in each of the third connecting walls 32 at locations aligned with these holes 22 for screws 62. The screw head 64 of each of these screws 62 is located on the rear side of the respective strip-shaped member 86. Thus, the screws 62 pull the formwork skin 50, the edge protection 12, the main body 4 and the strip-shaped members 86 of the reinforcement 84 together as a sandwich.

In the fifth exemplary embodiment of FIGS. 22 and 23, a front-side edge protection 12 and a rear-side reinforcement of the supporting structure 2 are provided. This embodiment differs from the embodiments described before primarily in that the edge protection 12 and the reinforcement 84 have been united with the main body 4 of the supporting structure 2 by so-called overmolding. For this purpose, four angular rail-like metal parts 90, which adjoin each other across corners and together form the edge protection 12, have been positioned in an injection mold in such a way that substantially only the respective second leg 37 of the edge protection 12 was not located inside the mold cavity of the injection mold. In the case of the reinforcement 84, two strip-shaped members 86 were positioned in the mold cavity of the injection mold such that they were almost completely enclosed by the injected plastic when the mold cavity was closed. The four angular rail-like parts 90 each have a miter bevel at their two ends, so that the second legs 37 of these members as a whole form a projecting edge for protecting the edge 56 of the formwork skin 50.

In FIG. 23, it can be seen that both the angular rail-shaped parts 90 and the strip-shaped members 86 each have a plurality of holes 92 distributed along their length. For positioning the angular rail-shaped parts 90 and the strip-shaped members 86 in the injection mold, these parts have been placed on graduated positioning pins, one pin per hole 92. For removing the supporting structure 2 together with the edge protection 12 and the reinforcement 84 from the mold cavity after injection molding, these positioning pins are withdrawn. The positioning pins leave small round holes 94 in the plastic material of the supporting structure 2. Instead of the angular rail-shaped parts 90, one can also position a frame-shaped part in the injection mold.

In all of the exemplary embodiments described, the edge protection 12 at the same time constitutes a reinforcement in the region of the front sides of the two longitudinal edge supports 6 and of the two transverse edge supports 8. However, according to the second aspect mentioned at the beginning, the invention also creates a supporting structure 2 in which no edge protection 12 is provided, but only a front-side and/or rear-side reinforcement of the supporting structure 2 or of the longitudinal edge supports 6 and/or of the transverse edge supports 8. For this purpose, it is conceivable e.g. that, instead of the edge protection 12, two or four strip-shaped members are provided which are formed similarly to the described strip-shaped members 86 on the rear side or which are formed similarly to the edge protection 12 but without a protruding edge 18.

It should be noted that the edge protection 12 does not necessarily have to cover the two longitudinal edges of the formwork skin 50 and the two transverse edges of the formwork skin 50. For example, for formwork panels 50 in which only the longitudinal edges of the formwork skin 50 or only the transverse edges of the formwork skin 50 are particularly at risk of being damaged, it may be sufficient to provide edge protection on these edges only.

Furthermore, it is pointed out that the reinforcement 84, which in the described exemplary embodiments was provided only in the region of the longitudinal edge supports 6, can also be provided “all around”, i.e. both on the longitudinal edge supports 6 (front side and/or rear side) and on the transverse edge supports 8 (front side and/or rear side).

In the invention the, in particular metallic, edge protection constitutes the projecting portion of the supporting structure 2 of the formwork panel that projects furthest on the outside, and thus provides particularly effective protection for the edge 56 of the formwork skin 50. The front-side reinforcement and/or the rear-side reinforcement 84 may be formed by parts whose dimension—as measured at right angles to the front side of the supporting structure 2—is smaller than the dimension measured in the direction parallel to the front side of the supporting structure 2. The front-side reinforcement and/or the rear-side reinforcement 84 may be concentrated on the region of the front side of the supporting structure (or the front side of the two longitudinal edge supports and/or the two transverse edge supports) and/or on the region of the rear side of the supporting structure 2 (or the region of the rear side of the two longitudinal edge supports and/or the two transverse edge supports), so that they provide an increase in strength of the supporting structure 2 in an optimum manner.

The described reinforcement 84 in the region of the rear side of the longitudinal edge supports 6 reinforces both the outside of the outer partial wall 28 in its rear-side end portion and the rear end of the double wall of the longitudinal edge support 6, which increases the stability against damage in these two regions.

The sectional view of FIG. 3 has shown the engagement of the extensions 24 in the holes 22. Such engagements also exist in the second, third and fourth embodiments, however in front of and to the rear of the drawing plane of FIGS. 17, 19 and 20, respectively.

When the edge protection 12 and/or the reinforcement 84 is made of long fiber reinforced plastic rather than sheet metal, these parts look quite similar to the sheet metal parts illustrated, possibly with small rounded portions instead of sharp corners and slightly thicker in the dimension measured perpendicular to the front side 80 of the supporting structure 2. 

1. A supporting structure of plastic construction for a formwork panel comprising a supporting structure and a formwork skin positioned on the front side of the supporting structure and attached to the supporting structure, wherein the supporting structure has two longitudinal edge supports and two transverse edge supports, characterized in that the supporting structure has a main body made of plastic, to which the two longitudinal edge supports and the two transverse edge supports belong, and, in the region of the front sides of the two longitudinal edge supports and/or of the two transverse edge supports, has an edge protection provided for protecting at least part of the edge of the formwork skin after attachment thereof to the supporting structure, wherein the edge protection is made of a material different from the material of said supports of the supporting structure and has a portion projecting forward from the respective said support; and/or that the supporting structure comprises a main body made of plastic, to which the two longitudinal edge supports and the two transverse edge supports belong, and in the region of the front sides of the two longitudinal edge supports and/or of the two transverse edge supports, and/or in the region of the rear sides of the two longitudinal edge supports and/or of the two transverse edge supports, has a reinforcement made of a material different from the material of said supports of the supporting structure.
 2. The supporting structure according to claim 1, characterized in that the edge protection and/or the (respective) reinforcement includes a plurality of material strips.
 3. The supporting structure according to claim 1 or 2, characterized in that the edge protection and/or the (respective) reinforcement has the shape of a rectangular frame.
 4. The supporting structure according to any one of claims 1 to 3, characterized in that the edge protection—as seen in a cross-sectional plane perpendicular to the longitudinal extension of the respective support—has a first leg substantially parallel to the front side of the respective support and a second leg projecting forward from the first leg.
 5. The supporting structure according to any one of claims 1 to 4, characterized in that the respective reinforcement has a horizontal rectangular cross-section—as seen in a cross-sectional plane perpendicular to the longitudinal extension of the respective support.
 6. The supporting structure according to any one of claims 1 to 5, characterized in that the edge protection and/or the (respective) reinforcement is made of metal or of long fiber reinforced plastic.
 7. The supporting structure according to any one of claims 1 to 6, characterized in that the edge protection and/or the (respective) reinforcement has a plurality of holes, and the respective support has a plurality of extensions on its front side and/or on its rear side, each of which projects into one of the holes.
 8. The supporting structure according to any one of claims 1 to 7, characterized in that the edge protection and/or the (respective) reinforcement is at least partially embedded in the plastic material of the respective support.
 9. The supporting structure according to any one of claims 1 to 8, characterized in that the main body thereof comprises the two longitudinal edge supports, the two transverse edge supports and a plurality of transverse intermediate supports.
 10. The supporting structure according to any one of claims 1 to 9, characterized in that the main body thereof is an integral plastic part.
 11. The supporting structure according to any one of claims 1 to 10, characterized in that the two longitudinal edge supports and/or the two transverse edge supports are formed as double walls with two partial walls and with first connecting walls therebetween, which have planes of extension transverse to the longitudinal extension direction of the respective support.
 12. The supporting structure according to any one of claims 1 to 11, characterized in that the two longitudinal edge supports and/or the two transverse edge supports are formed as double walls with two partial walls and with a second connecting wall therebetween on the front side of the double wall or with a third connecting wall therebetween on the rear side of the double wall.
 13. The supporting structure according to any one of claims 9 to 12, characterized in that at least a partial number of the transverse intermediate supports comprises two partial walls that are spaced further apart from one another on the side closer to the front side of the supporting structure than on the side further away from the front side of the supporting structure.
 14. The supporting structure according to any one of claims 9 to 13, characterized in that at least a partial number of the transverse intermediate supports—as measured perpendicular to the front side of the supporting structure—is of lesser height than the supporting structure and, on the side further away from the front side of the supporting structure, terminates at a distance from the rear side of the supporting structure.
 15. The supporting structure according to any one of claims 9 to 14, characterized in that, on its front side, there is a supporting plane for the formwork skin, to which regions on the front sides of the two longitudinal edge supports, regions on the front sides of the two transverse edge supports and regions on the front sides of the transverse intermediate supports contribute.
 16. A formwork panel, characterized in that it comprises a supporting structure according to any one of claims 1 to 15 and a formwork skin positioned on the front side of the supporting structure and attached to the supporting structure.
 17. The formwork panel according to claim 16, characterized in that the formwork skin is made of plastic.
 18. The formwork panel according to claim 16 or 17, characterized in that the edge protection and/or the reinforcement provided in the region of the front sides of the respective supports is positioned in sandwich-like manner between the front sides of the respective supports of the supporting structure and the formwork skin, and in that, by fastening of the formwork skin to the supporting structure, there is formed at the same time a fastening of the edge protection and/or the reinforcement to the formwork panel.
 19. The formwork panel according to any one of claims 16 to 18, characterized in that the formwork skin has clip extensions formed on its rear side, by means of which it is fastened to the supporting structure.
 20. The formwork panel according to any one of claims 16 to 19, characterized in that the formwork skin has extensions formed on its rear side; and in that the formwork skin is fastened to the supporting structure by means of screws which are threadedly engaged in at least a partial number of these extensions from the rear side of the supporting structure.
 21. The formwork panel according to claim 20, characterized in that at least a partial number of said screws each extends through a hole of the reinforcement provided in the region of the rear sides of the respective supports, whereby said reinforcement is fastened to the formwork panel.
 22. A method of manufacturing a supporting structure according to any one of claims 1 to 15, characterized in that the edge protection is at least partially and/or the reinforcement is at least partially positioned in an injection mold and is at least partially embedded in the plastic of the supporting structure by overmolding when the supporting structure is injection molded. 